This invention concerns control of the atmosphere in an operator enclosure of a self-propelled vehicle and, more particularly, the arrangement and combination of components within the enclosure of an off-the-road vehicle exposed to heavy concentrations of airborne dust and debris.
Concern for operator safety and comfort leads to the development of increasingly sophisticated operator enclosures (which, however, are still generally referred to as cabs). It is well-known that modern cab design deals not only with ergonomic considerations but also with the more passive environmental factors such as roll-over protection, isolation from noise and preservation of a comfortable and clean atmosphere. The present invention is concerned principally with the latter but improvement of atmosphere control in cabs is clearly most advantageously used in an operator station or enclosure in which other comfort and safety considerations have been adequately provided for. It is well-known, in a completely encloed cab, to provide an atmosphere control system which takes in and filters outside air, heats or cools the air as required, and circulates it in the cab while maintaining pressure in the cab slightly above atmospheric, so as to discourage the entry of dust or other contaminants through, for example, imperfectly sealed doors or windows. Efforts are still being made to improve the efficiency, serviceability and compactness of such systems. Means are sometimes provided for precleaning the intake air but typically precleaners are remote from the main components of the system and unsightly and fitted as an attachment or add-on rather than integrated into the system.